Improved coppee-coated iboni eolls foe peintihg and hnishifg



gnite?! tatrs. gaunt @ffirz.

IMPROVED COPPER-COATED IRON ROI-LS POE PRINTING AND FINISHING.

an fitlnbnlt rifzmhit it llgzse Enters- @ntmtimh making part f life same.

1'0 WHOM IT MAY CONCERN:

Be it known that I,,ALFRED PARAF, of Mulhouso, in the Empire of France, have invented certain new and useful improvements in the Method of Coating Iron with Copp'eri'n' the Manufacture of Printing or Finishing Rollers; and I hereby declare the following to be a full, clear, and exact description of the same.

,Iron has heretofore been 'coatedwith copper, but such coating: has been but imperfectly combined with the 1 iron,- so that it could only he used in very thin layers for ornamental or protecting purposes; and it has been found utterly. impracticableto give to iron'rollers a coating of copper sufiiciently thick to enable it tobe engraved for printing purposes, as such coating could not be made to adhere to the iron.

The object of my invention is, therefore, to intimately combine a coating of copper, of any desired thicxness, with iron; and this I have efi'ected by causing the initial coating to form' an'intimate union with the iron. To this effect I proceed as follows: Theroller is formed of cast iron, which must not be too hard, so that it may be easily turned and polished. After the roller is cast, it is'necessary to turn it'in a lathe to the required dimensions, after which it is filed and finally polished, between two pieces. of wood, with em'ery and water. It is then well cleaned, and placed in a nooden boii' which contains a. copper solution and a copper plate. The copper bath I prepare in thefollowing manner: three hundred grammes sulphite of soda; five hundredgramm'es cyanide of potassium; three hundred and fifty grammes acetate of copper; twb hundred grammes ammonia; twenty-five litres of' water.- The bath is as alkaline as possible, for an acid solution will produce a finely granulated or crystalline deposit, which prevents the copper from adhering to the iron. The copper plate should be put in communication. with the positive pole of an electric pile, and the iron roller with the negative'poie of the same. After the electricity has been on for thirty orforty minutes, the roller is well brushed with a brass or copper brush, in order to-take away the whole amount of copper deposited during'thcse thirty ouforty minutes. Care should be taken in this operation to lieep the roller immersed in the copper bath, and to take out that part only which is-br'ushed. After this the reaction is allowed to go on for four or six days, according to the temperature, during which time eight of Bunsens elements should be used, which, of course, have to be in working order all the time. n At the expiration of this-time the roller is taken out, washed thoroughly in water, closed at each end, then immersed for half a minute in nitric acid, then thoroughlywashed again in water, and againpluced in contact with electricity in a copperobath which prepare in the following manner: twenty-two parts sulphate of copper seven parts sulphate of soda; ten part-s sulphuric acid, and enough water to make it stand 30 T. For the second immersion four of Bunsens elements are suflicicnt. The roller must remain in this bath for from eight to ten days, and it is then taken out, well crashed, turned, polished, after which it will be ready for engraving. By thisprocess a. heavy coating of copper is formed, which is combined and united intimately with the iron. The preliminary operation of'brushing the primary copper deposits from iron is quite essential to this result, as the iron is not passive a't first to the action of the pile, and consequently the coating formed in the first few minutes after the iron has been immersed in the bath and subjected to the action of the electric current, does not adhere with the requisite tenacity, The copper coating, by the process above described,-

may be of any desired thickness, so that then-oil can be engraved, and used in the place of the ordinary roll employed in print-works for printing cr'fi-nishing calico and other goods. v

Having described my inventiozn-and the manner in which. the same is or may be carried into effect, what I claim, and desire to secure by Letters Patent, is r I i As a new manufacture, making printing or finishing rollers of cast iron, and coating the same with copper, substantially in the mariner and by the means herein specified.

In testimony whereof I have signed my name to this specification before two subscribing witnesses.

ALFRED PARAF.

Witnesses:

A. POLLOK. Emu F Bnown. 

